001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.model;
018
019import javax.xml.bind.annotation.XmlAccessType;
020import javax.xml.bind.annotation.XmlAccessorType;
021import javax.xml.bind.annotation.XmlRootElement;
022
023import org.apache.camel.Predicate;
024import org.apache.camel.Processor;
025import org.apache.camel.model.language.ExpressionDefinition;
026import org.apache.camel.processor.FilterProcessor;
027import org.apache.camel.spi.Metadata;
028import org.apache.camel.spi.RouteContext;
029
030/**
031 * Filter out messages based using a predicate
032 *
033 * @version 
034 */
035@Metadata(label = "eip,routing")
036@XmlRootElement(name = "filter")
037@XmlAccessorType(XmlAccessType.FIELD)
038public class FilterDefinition extends ExpressionNode {
039
040    public FilterDefinition() {
041    }
042
043    public FilterDefinition(ExpressionDefinition expression) {
044        super(expression);
045    }
046
047    public FilterDefinition(Predicate predicate) {
048        super(predicate);
049    }
050
051    @Override
052    public String toString() {
053        return "Filter[" + getExpression() + " -> " + getOutputs() + "]";
054    }
055    
056    @Override
057    public String getLabel() {
058        return "filter[" + getExpression() + "]";
059    }
060    
061    @Override
062    public FilterProcessor createProcessor(RouteContext routeContext) throws Exception {
063        return createFilterProcessor(routeContext);
064    }
065    
066    @Override
067    protected FilterProcessor createFilterProcessor(RouteContext routeContext) throws Exception {
068        // filter EIP should have child outputs
069        Processor childProcessor = this.createChildProcessor(routeContext, true);
070        return new FilterProcessor(createPredicate(routeContext), childProcessor);
071    }
072
073    /**
074     * Expression to determine if the message should be filtered or not. If the expression returns an empty value or <tt>false</tt>
075     * then the message is filtered (dropped), otherwise the message is continued being routed.
076     */
077    @Override
078    public void setExpression(ExpressionDefinition expression) {
079        // override to include javadoc what the expression is used for
080        super.setExpression(expression);
081    }
082}